1. Field of the Invention
The present invention relates to a method of forming a dense layer on a concrete surface such as a concrete floor or the like.
2. Description of the Prior Art
In a known method of forming a dense concrete surface, cement paste or mortar having a low water-cement ratio of 15%-23% is placed on a base plate, and the cement paste or mortar is pressed and spread by using an ultrasonic vibrator. It is then left to stand, thereby forming a dense layer having a thickness of 1-3 mm (Japanese Patent Laid-Open No. 44705/1989.
In the above-described conventional method, the material used is cement paste or mortar having qualities of becoming spread and fluidized upon receiving ultrasonic vibrations. In the case of concrete in which coarse aggregates are mixed, a large amount of coarse aggregates exists in the vicinity of the surface of placed concrete, so that there is a problem in that a thick and dense layer cannot be formed on the concrete surface. In addition, in accordance with the conventional method, since cement paste or mortar is placed on the base plate and is pressed by means of an ultrasonic vibrator, there is the problem that the method cannot be applied directly to fieldwork where concrete is placed on a plate floor or on the ground as in the case of a road.